Warp-knitted pile fabric

ABSTRACT

A warp-knitted fabric is made of wales of chain stitches, transverse weft threads, and pile warp threads anchored in successive courses and adjacent wales in the chain stitches to form pile loops between the anchored portions thereof.

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1 68B hhhh Maw mm WARP-KNITTED PlLE FABRIC BACKGROUND OF THE INVENTION The present invention relates to a fabric knitted in a textile machine, such as a stitch-knitting, warp-knitting, or Raschel machine.

A warp-knitted fabric is known in which a single weft thread is knitted through a warp thread system in such a manner that portions of the weft thread pass perpendicular to the direction of the wales through front loops and back loops of the warp threads, forming at the edges of the knitted fabric reversing arcs, a single weft thread being inserted throughout the entire length of the warp-knitted fabric. A knitted fabric of this type cannot be patterned with weft threads of different colors or yarn number, and if the weft thread is omitted in one or several courses, the following weft thread is longitudinally inserted on the side of the fabric, and must be cut off during the final processing.

Another known warp-knitted fabric is made in the same way, but the weft thread is knitted simultaneously with the warp threads in-the marginal wales.

Another known warp-knitted fabric has weft threads which are transversely slanted to the wales of the fabric angles less than 90. This fabric requires irregular mutual crossing of the weft threads, so that the fabric is of irregular density.

The warp-knitted fabrics according to the prior art have also the disadvantage that they cannot be provided with plush or pile loops. Other knitted fabrics are known in which plush loops are formed on the knitted fabric either of the back loops of the threads, or of additionally inserted pile threads. These fabrics have the disadvantage that the backing is irregular and the wefts do not form a right angle with the warps so that the appearance and strength of the fabric is detrimentally influenced.

In another known method, fibrous weft material is inserted into the fabric in lengths corresponding to the required weft lengths, and helical elements are used for providing substantially parallel courses of weft threads, gripping at both sides of the machine loops of several endless-weft-thread systems and conveying the threads continuously to the working station at a textile machine. A disadvantage of this arrangement resides in the fact that the weft threads are subjected to long and continuously increasing stress, requiring operation of the machine at a relatively low speed if frequent yarn breakages are to be avoided. Only high-quality yarn can be used,'which is an economic disadvantage.

According to another method of the prior art, a weft-inserting guide inserts the weft thread after each revolution of the machine from one side to the other side of the fabric, which means that the weft-inserting guide performs one working cycle during two machine revolutions. The disadvantage of this arrangement is that the weft-inserting guide has to traverse substantially the whole width of the machine, and that color patterning, and patterning by transverse strips without weft threads, cannot be carried out.

Another method of the prior art provides a weft-thread system continuously moving in the direction of the advancement of the fabric, and producing slanted weft threads in the same. A reversing carriage lays the weft-thread system into a continuously moving conveyor. The obtained product is of comparatively low tensile strength since the weft threads are slanted and irregularly cross each other. Also, the appearance of the fabric is not satisfactory.

SUMMARY OF THE INVENTION It is an object of the invention to overcome the disadvantages of the prior art, and to produce a warp-knitted fabric having separate weft threads.

Another object of the invention is to produce a warpknitted fabric of great strength and pleasing appearance.

Another object of the invention is to produce a warpknitted fabric having separate weft threads, and additional warp threads forming plush loops.

Another object of the invention is to form and to supply to the warp-knitting machine, weft threads having a length corresponding to the width of the warp-knitted fabric.

Another object of the invention is to fasten the diagonal plush or pile loops to one side of the fabric by the chain stitches of the warps.

In accordance with the invention a warp-knitted fabric is made of wales of chain stitches, transverse weft threads, and

pile warp threads anchored in successive courses and adjacent wales in the chain stitches to form pile loops between the anchored portions thereof.

Due to the fact that weft threads of a length corresponding to the width of the warp-knitted fabric are continuously transported to the warp-knitting machine, the weft threads can be arranged at irregular intervals, or at equal intervals with the yarn number, and the color of the weft threads can be varied. The usefulness of the fabric is increased when both the warp and weft system are arranged at irregular intervals. Also, it is advantageous to make the plush loops of the fabric only a part of the surface of the same.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims.

The invention itself, however, both as to its construction .and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary perspective view illustrating a pile fabric according to the invention;

FIG. 2 is a schematic plan view illustrating an apparatus according to one embodiment of the invention;

FIG. 3 is a schematic cross-sectional view of the apparatus shown in FIG. 2;

FIG. 4 is a diagram illustrating the motion of the apparatus of FIG. 2;

FIG. 5 is a fragmentary perspective and schematic view illustrating a modification of the apparatus of FIG. 3;

FIG. 6 is a fragmentary plan view of another embodiment of the invention using pneumatic means for supplying the weft threads;

FIG. 7 is a schematic front elevation, partially in section, illustrating the apparatus of FIG. 6;

FIG. 8 is a schematic side elevation illustrating the apparatus of FIGS. 6 and 7;

FIG. 9 is a fragmentary side view, partially in section, illustrating a cam operation for delivering weft threads to the warp knitting machine;

FIG. 10 is a fragmentary side view illustrating a device for opening the grippers of the transporting conveyor;

FIG. 11 is a schematic plan view illustrating the operation of the grippers of a supply conveyor in the embodiment of FIGS. 3 and 5;

FIG. 12 is a fragmentary side view illustrating a detail of the device shown in FIG. 11;

FIG 13 is a schematic plan view illustrating a fabric according to the invention; and

FIG. 14 is a schematic plan view illustrating a patterned fabric according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fabric of the invention receives weft threads from apparatus shown in FIGS 2 to 12. Referring first to FIG. 2, an endless conveyor 6 has two endless chains 6 and 6" guided over chain wheels 7, 8 driven by a shaft 17, and chain wheels 9, 10 driven by a shaft 14. A motor 11 drives shaft 14 by means of a gear transmission 13 and a chain drive 12, and also drives a shaft 15 which is connected by a gear transmission 8 with shaft 17. The drive of conveyor 6 must be coupled with the drive of the stitch-knitting machine, which is best accomplished by driving the stitch-knitting machine by the same electric motor over a gear transmission when a regular distribution ofweft threads 2, which are transported by chains 6' and 6" of conveyor 6, is required. The weft threads transported by conveyor 6 are inserted between comb structures 28 and 19 which are part of the stitch-knitting machine which includes a row of needles 20 reciprocable to pass into the spaces between the teeth of comb-shaped structures 18 and 19, the latter effecting the knocking off of the loop.

Grippers 21 are mounted on. conveyor chains 6' and 6", each gripper including a stationary jaw 22, and of a movable jaw 23 mounted for angular movement on pins 24 on chains 6 and 6", as shown in FIGS. 9 and 10. The stationary jaws 22 are parts of the chain links which are connected by pins 24. Springs 23a bias the movable jaws 23 toward the stationary jaws 22. The clamping of the weft threads 2 by grippers 21 is improved by forming the stationary jaws 22 with a Ushaped cross section forming a channel into which the movable jaw 23 advances so that the weft thread is more reliably held in the channel by the movable jaw 23.

The movable jaws 23 have tails or fingers 25 cooperating with a vertically movable control member comb 27 which has a row of teeth 26. The mechanism for moving control member 27 is not shown, since it is not an object of the invention.

Weft-supplying conveyor means are provided which include a pair of conveyor chains 30 passing over chain wheels 31 driven by transmission means from shaft 15. Conveyor chains 30 are connected by support bars 29 each of which carries a row of grippers 28, see also FIGS. 3, 5, 11, and 12. Each gripper 28 has a pair of jaws 32', 32" connected by a pin. Movable jaws 32' are operated by a control rod 33' having lugs respectively engaging the tails of movable jaws 32', and having a follower roller 34' cooperating with a stationary cam 35' extending along one of the conveyor chains 30, as shown in FIGS. 11 and 12. The othermovable jaws 32" are operated in the same manner by a control rod 33" which has a cam follower roller 34" cooperating with a stationary cam 35" extending along the other conveyor chain 30, as shown in FIGS. 11 and 12. The movement of grippers 28 is transverse to the movement of grippers 21, as best seen in FIGS. 2 and 5.

The weft-supply means further include cross-wound packages or bobbins 38 from which weft threads are respectively guided through stationary eyes 37 and stationary guide tubes 36, mounted on supporting means 40, as best seen in FIG. 5. The same or different threads may be supplied by packages 38, but each system or series of weft threads 2 has a number corresponding to the number of supply packages 38. A corresponding number of cutting scissors 39 is located between guide tubes 36 and grippers 21 on conveyor chain 6.

Supporting means 40 has bearing bushings 41a and 41b in which support rods 42 are mounted for vertical movement, as shown in FIGS. 3 and 5. Each support rod 42 carries a cam follower roller 43 cooperating with cam means 44 so that carriers 45a, 45b connected to the upper ends of support rods 42, can be raised and lowered. Carriers 45a and 45b have a channelshaped main part closed by a cover plate so that inner cavities are formed for guiding the links of conveyor chains 6' and 6", while grippers 21 are located outside of the cavities, supported by carriers 45a and 45b. Consequently, rotation of cams 44, which are provided at both ends of conveyor chains 6' and 6", will effect raising and lowering of conveyor chains 6' and 6".

FIG. 3 illustrates a minor modification of the construction as shown in FIG. since instead of cams 44, circular eccentrics are mounted on a driven shaft, and are located in corresponding openings of support bars 42 which carry carriers 45a and 45b.

Another modification of the weft-supply means is shown in FIGS. 6, 7 and 8.

Weft threads 2 are drawn from the packages 38 by pairs of transporting rollers 51a, 51b and transported to a thread accumulator 49. An air-guiding body 46 has a number of nozzles 47 for blowing airstreams through guide tubes 48 into which weft threads 2 are blown. Cutting means 50 are located between the nozzles 47 and tubes 48. As in the embodiment of FIGS. 3 and 5 carriers 45a and 45b support the conveyor chains 6' and 6", and. are mounted on support bars 42 operated by eccentric members 52 as described with reference to the modification of FIG. 3.

At the working station at the end of conveyor chains 6, 6", an arcuate cam 54 is disposed, as shown in FIG. 9, cooperating with the tails of grippers 21 for opening the same against the action of springs 230.

For producing the pile fabric shown in FIG. 1, a known plush comb has to be attached to the stitch-knitting machine.

Chains 6, 6" continuously transport weft threads 2, held by pairs of grippers 21, toward combs 18 and 19 of the stitching machine, and new weft threads are continuously supplied to grippers 21 by the weft-supply means shown in FIGS. 3 and 5, or by the weft-supply means shown in FIGS. 6, 7 and 8. When a weft thread 2 held by a pair of grippers 21 arrives at the ends of the loops of chains 6', 6", cam 54 is effective to open grippers 21 by engaging the tails of the movable jaws 23 so that the weft threads are released. Before opening grippers 21, the same press the weft thread 2 from below against the front faces of all needles 20. At this moment, kinking takes place, the latches of needles 20 are closed, and the weft threads can slide over the point of needles 20 to the rear face of the same, so that each weft thread 2 is knitted into the fabric between bight portions 3 and loop portions 4 of warps 1, see FIG. 1. When cam 54, see FIG. 9, has opened the respective pair of grippers for releasing the weft thread, it permits the grippers 21 to close again and to move in empty condition in the direction opposite to the direction S with the lower run of conveyor chains 6, 6". Pairs of closed grippers 21 pass over chain wheels 7 and 8, and move again in the direction S toward the weft supply conveyor means 30.

In the embodiment of FIG. 5 and its modification shown in FIG. 3, the endless conveyor chains 30 move in the direction of the arrow P.

The weft-supply grippers 28 carried by support bar 29 on the lower run of conveyor means 30 have clamping jaw portions located at the horizontal level of the guide tubes 36 from which weft thread ends project, and a small distance above the level of the jaws of transporting grippers 21, as best seen in FIG. 3.

When the grippers 28 approach the guide tubes 36, the earns 35' and 35", see FIG. 11, operate the control rods 33' and 33" to open grippers 28 so that the spread jaws 32', 32" assume a position located on opposite sides of a weft thread end hanging from the end of the respective guide tube 36. When the row of grippers 28 is in this position, cams 35 and 35" permit the closing of grippers 28 so that all weft thread ends projecting from guide tubes 36 are gripped, and the weft threads 2 are drawn through guide tubes 36, and eyes 37 and unwound from the respective packages 38. When the respective row of grippers 28, clamping weft threads 2, has moved beyond the position shown in FIG. 3 to a position located substantially above carrier 45b, and outwardly of the row of grippers 21 on the same, a portion of the pulled-out weft thread 2 extends between a pair of grippers 21, still located above the same.

FIG. 4 schematically shows this position and indicates the movement of conveyor means 6 in the direction S, the movement of the weft threads 2 in the direction of the arrow P to a position 2a, and the additional movement in the direction of the arrow T by which the new weft thread 2a is placed in the grippers 21 and is moved by a conveyor means 6 toward the working station.

When the weft thread 2 has been pulled out completely by the respective row of grippers 28, the cams 44 in the embodiment of FIG. 5, and the eccentric members 52 in the embodiment of FIG. 3 turn to a position for raising support bars 42 with carriers 45a and 45b, and grippers 21.

The control member 26, shown in FIG. 10, is simultaneously moved to engage tails 25 of grippers 21 so that jaws 22, 23 open before arriving at the level of the weft thread 2 which extends between tube 36 and the gripper 28 which is now in the proximity of the carrier 45b, and on the right side of the right hand gripper 21, as viewed in FIG. 3. When carriers 45a and 45b are in the higher position, they stop momentarily due to the shape of cams 44 or 52, and the teeth 27 of control member 26 release tails 25 so that the spring-biassed jaws 22, 23 close and grip the weft thread 2a at the higher level.

The motions of conveyors 6 and 30, and of control member 26 are synchronized in such a manner that the first weft thread pulled out by the first gripper 28 is located directly above the first pair of grippers 21 so that the same can grip the weft thread after a straight vertical motion. The following pulledout weft threads are located above other pairs of grippers 21 when carriers 45a and 45b move upward to the higher level with grippers 21. All pairs of grippers 21 are supplied with a weft thread 2b, and none remains empty. At the proper moment, scissor means 39, see FIG. 2, are operated to cut off weft thread 2b from the weft-thread portion in tube 36 such a distance from the latter that it can be gripped by a gripper 28. If no particular pattern is desired, each pair of grippers 21 transports only a single weft thread 2b in the direction S toward the knitting station 18, 19, 20. It is evident that grippers 28 must not be opened before control member 26 operates grippers 21 to clamp the weft thread. As soon as weft threads 2b are located between the jaws 22, 23 of grippers 21, tails 25 are released by the teeth 27 of control member 26, see FIG. 10, and the weft threads 2b are gripped by the springbiased grippers 21, and upon advancement of conveyors 6 and 30, weft threads 2b are pulled out of grippers 28 opened by cams 35', 35" when further moving in the direction P. When the transfer of the weft thread has been effected, cams 44, or 52 move carriers 45a, 45b with pairs of grippers 21 down to the lower position.

Only one support 29 with the row of grippers 28 is at any time supported by the lower run of conveyor chains 30, while the other support 29 is located on the upper run, and moves in opposite direction. The number of weft threads which can be simultaneously supplied to the grippers 21 of conveyor 6 depends on the speed of the machine at which the weft threads 2 are knitted into the fabric, and the higher the speed of the machine is, the more weft threads have to be supplied simultaneously to pairs of grippers 21.

In the pneumatic weft-supply apparatus shown in FIGS. 6, 7 and 8, a number of weft threads determined by the number of packages 38, transporting rollers 51a, 51b, and nozzles 47, is simultaneously blown in a direction perpendicular to the continuous motion of weft threads by grippers 21 of conveyor 6. Weft threads 2 drawn by transporting rollers 51a, 51b and accumulated in accumulator 49, are blown by nozzles 47 into and through tubes 48, passing through a cutting device 50.

The feeding rollers 51a and 51b are so controlled that they supply the required length of weft threads in cooperation with a measuring mechanism, not shown. When rollers 51a, 51b stop, the streams of air continuously blown out of nozzles 47 maintain the weft threads 2 in a straight condition so that the ends of the weft threads project out of the ends of tubes 48 and are located above grippers 21 on conveyor chain 6". Another portion of the weft threads is located above grippers 21 supported by conveyor chain 6.

When each weft thread is located above a gripper 21, carriers 45a and 45b are raised by eccentric members 52 to a position in which the clamping jaw portions of jaws 22, 23 are located on opposite sides of the respective weft thread in an open position assumed under the control of control member 26, whereupon the latter releases the tails 25 of grippers 21, permitting springs 23a to close the jaws 22, 23 so that the weft thread is gripped by a pair of grippers 21. Cutting devices 50 are operated by cam means, not shown, to cut off the weft thread between the respective nozzles 47 and grippers 21, whereupon earns 52 return carriers 45a, 45b with conveyor chains 6', 6" and pairs of grippers 21 holding weft threads so that the weft threads are again at the lower level at which they are supplied to the knitting machine.

As is shown by the schematic cross section 480 of a tube 48 in FIG. 7, the tube 48 has a bottom slot extending in longitudinal direction so that the weft thread held between a pair of grippers 21, can move downwardly with the same. Feeding rollers 51a, 51b are now operated to pull measured lengths of weft threads from packages 38, whereupon the weft threads are blown into the tubes 48. 9

When it is desired to produce a patterned fabric, the warp thread 1 and the weft threads 2 are patterned by omitting warp threads 1 and weft threads 2 at places determined by the pattern. As shown in FIG. 14, groups of four wales are separated where groups of five warp threads were not supplied, and groups of five weft threads 2 are separated where groups of three weft threads 2 were not supplied. The threading of the warp thread 1 and weft threads 2 is carried out according to the desired pattern. It is also possible to determine the distribution of the weft threads 2 by means of a Jacquard-patterning mechanism, not shown, which effects swinging out of grippers 28 in the direction of the movement of conveyor 6.

In order to manufacture a pile fabric with plush loops, as shown in FIG. 1, pile loop portions 5 are formed by pile warp threads 1' and disposed in the fabric by placing the same under the needles 20, so that each anchoring portion la is caught by two loop portions 4 of two adjacent chain stitches formed of warp threads 1 in the same wale.

FIG. 1 shows warp threads 1 forming wales A-D of chain stitches a to d, each of which has a bight portion 3 and a loop portion 4 passing through the the bight portion of an adjacent chain stitch in the same wale. The anchoring portions la pass through two adjacent chain stitches'and are held by the loop portions 4 of the same. Pile warp threads 1 have alternate pile portions 5, and anchoring portions 1a located in adjacent wales A-D and successive courses.

A fabric made in accordance with the present invention is suitable particularly for decorative fabrics, as used for covering furniture, but may also be used for the manufacture of underwear and other textile fabrics for which no expansibility is desirable. The fabric is also suitable for carpets, carpet backings, mats, base fabrics for needle-tufted textiles, and other purposes.

.It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of warp-knitting apparatus differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus and machine for making a warpknitted pile fabric, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

1. A warp-knitted pile fabric comprising at least one system of warp threads consisting of chain stitches forming a plurality of wales and courses, said chain stitches having bight portions, and loop portions passing through said bight portions of adjacent chain stitches in the same wale and in an adjacent course, respectively; a system of weft threads located in said courses, between said bight portions and said loop portions of the chain stitches of the respective course; and a system of pile warp threads, each pile warp thread having alternate pile portions and anchoring portions, said pile portions extending between different wales and courses, and alternate anchoring portions being located in different wales and courses, each anchoring portion passing between the bight portions and loop portions of two adjacent chain stitches located in the same wale in two successive courses so that said pile portions form an anchored pile.

2. A warp-knitted pile fabric as claimed in claim 1 wherein said alternate anchoring portions of each pile warp thread are located in adjacent courses and adjacent wales; and wherein each pile warp thread extends along a zigzag path between adjacent wales and courses.

3. A warp-knitted fabric as claimed in claim 1 wherein each weft thread is located in one of said courses, respectively, passing between said bight portions and loop portions of the chain stitches of the respective course.

4. A warp-knitted fabric as claimed in claim 1 wherein said pile portions of said pile warp threads form pile loops only on a part of the surface of the fabric.

5. A warp-knitted'fabric as claimed in claim 1 wherein said wales include groups of adjacent wales, said groups being separated from each other in the direction of said courses.

6. A warp-knitted pile fabric as claimed in claim 1 wherein said alternate anchoring portions of each pile warp thread are located in adjacent courses andadjacent wales; and wherein each pile warp thread extends along a zigzag path between adjacent wales and courses; and wherein each weft thread is located in one of said courses, respectively, passing between said bight portions and loop portions of the chain stitches of the respective course.

7. A warp-knitted fabric as claimed in claim 6 wherein said pile portions of said pile warp threads form pile loops only on a part of the surface of the fabric; wherein said wales include groups of adjacent wales, said groups being separated from each other in the direction of said courses. 

1. A warp-knitted pile fabric comprising at least one system of warp threads consisting of chain stitches forming a plurality of wales and courses, said chain stitches having bight portions, and loop portions passing through said bight portions of adjacent chain stitches in the same wale and in an adjacent course, respectively; a system of weft threads located in said courses, between said bight portions and said loop portions of the chain stitches of the respective course; and a system of pile warp threads, each pile warp thread having alternate pile portions and anchoring portions, said pile portions extending between different wales and courses, and alternate anchoring portions being located in different wales and courses, each anchoring portion passing between the bight portions and loop portions of two adjacent chain stitches located in the same wale in two successive courses so that said pile portions form an anchored pile.
 2. A warp-knitted pile fabric as claimed in claim 1 wherein said alternate anchoring portions of each pile warp thread are located in adjacent courses and adjacent wales; and wherein each pile warp thread extends along a zigzag path between adjacent wales and courses.
 3. A warp-knitted fabric as claimed in claim 1 wherein each weft thread is located in one of said courses, respectively, passing between said bight portions and loop portions of the chain stitches of the respective course.
 4. A warp-knitted fabric as claimed in claim 1 wherein said pile portions of said pile warp threads form pile loops only on a part of the surface of the fabric.
 5. A warp-knitted fabric as claimed in claim 1 wherein said wales include groups of adjacent wales, said groups being separated from each other in the direction of said courses.
 6. A warp-knitted pile fabric as claimed in claim 1 wherein said alternate anchoring portions of each pile warp thread are located in adjacent courses and adjacent wales; and wherein each pile warp thread extends along a zigzag path between adjacent wales and courses; and wherein each weft thread is located in one of said courses, respectively, passing between said bight portions and loop portions of the chain stitches of the respective course.
 7. A warp-knitted fabric as claimed in claim 6 wherein said pile portions of said pile warp threads form pile loops only on a part of the surface of the fabric; wherein said wales include groups of adjacent wales, said groups being separated from each other in the direction of said courses. 